This proposal contains a series of experiments designed to evaluate preservation with respect to the response inhibition hypothesis. The response inhibition framework has received considerable attention both in animal and human research, with little attention paid to alternative possibilities that might be able to provide a more functional explanation tied to animal learning theory. Identifying whether or not the behavioral deficits identified as perseverative is important not only because it has implications for the treatment of FAS but because this distinction may be able to provide a tool to differentiate FAS from other learning disorders.